PCF8574PWR

I/o Expanders Overview

The PCF8574PWR is an 8-bit I/O expander for the two-line bidirectional I2C bus, designed for operation with a supply voltage range of 2.5 V to 6 V. It provides general-purpose remote I/O expansion via serial clock (SCL) and serial data (SDA) pins. The device features an 8-bit quasi-bidirectional I/O port (P0–P7) with latched outputs capable of directly driving LEDs. Each I/O can function as input or output without a data-direction control signal. At power-on, the I/Os are high, activating only a current source to VCC. The component includes an open-drain interrupt output (INT) and supports address configuration through three hardware pins.

I/o Expanders Feature Summary

• I2C to parallel-port expander functionality
• Open-drain interrupt output capability
• Latched outputs with high-current drive capability
• Quasi-bidirectional I/O ports without direction control signals

I/o Expanders Applications

• Telecom shelters: filter units
• Servers
• Routers (telecom switching equipment)
• Personal computers
• Industrial automation

I/o Expanders Procurement Notes

Verify the specific package variant against the datasheet, as the PCF8574 family includes TSSOP-20 (PW), SOIC-16 (DW), PDIP-16 (N), TVSOP-20 (DGV), and VQFN options. Confirm that the ordering suffix matches the required physical footprint and pinout. Ensure the selected part number aligns with the intended PCB layout dimensions and thermal requirements for the target application environment.

I/o Expanders Selection Notes

Select this component when GPIO resources on a microcontroller are limited and I2C connectivity is available. The device operates within a wide voltage range suitable for various logic families. Consider the quasi-bidirectional nature of the ports; inputs require writing a high state before reading. Evaluate the interrupt line requirement if asynchronous event detection is necessary for system efficiency.

I/o Expanders Part Context

The PCF8574 series serves as a remote I/O expander for microcontrollers using the I2C interface. It expands standard I/O capabilities by converting serial I2C data into parallel I/O signals. The device simplifies system design by reducing the number of direct connections required between the processor and peripheral devices, allowing for more compact circuit layouts.

I/o Expanders Replacement Considerations

PCF8574APWR